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Telescope: how it works

Telescope: how it works

We talk about great leaps in science and technology because we at New Source Corp work with NASA, Boeing, Northrup Grumman, and Lockheed Martian just to mention a few of the major players in the race to use technology to move forward, to learn more, and to explore the unexplored. Missions to Mars are on the horizon but the next step will not be made with our feet. A new telescope has been created, but that sentence alone does it no justice at all. A great deal of explaining will be needed to truly understand this engineering feat, amazing technological teaching tool, and the discoveries it is about to reveal.

Where did the telescope come from?

Everyone over the age of roughly 5 knows that a telescope is scientific tool to see things smaller than our eyes can usually see, but there’s more to it than that. Typically people confuse telescopes for microscopes, if not for their use in movies especially pirates, then for their use in design. Like microscopes, the original design for telescopes was a tube with lenses in it, like those you see being pulled apart by a sailor on a ship. This is where the term telescoping comes from, and though the first telescopes created in 1600 really were tubes with lenses, by the middle of the century, that design had been upgraded not once but twice. It was Newton’s idea to use mirrors instead of lenses but it was Cassegrain that created the design we still use today.

How does a telescope work?

If we use the picture as a comparison, the bowl of cereal could represent the large mirror. The spoon would then be second mirror, but it would have to be turned upside down. Then there would be a hole in the bowl for the final light to travel through to be viewed, but to be more specific:

  • Light shines on a large mirror. The mirror has a parabolic shape: like a wide, nearly flat bowl. This shape causes the reflection of the image to shrink as it points at another mirror.
  • The second mirror is mounted directly above the center and at a specific distance away from the first. It has a hyperbolic shape: also shaped like a wide, flat bowl, just much smaller and thicker. This mirror also causes the reflection of the image to shrink again as it points directly into the center of the first mirror.
  • In the center of the first mirror is a hole that is the correct size to allow the shrunken reflected image to pass through to an eyepiece. The eye piece can be for simple viewing or have filters added to it so some parts of the image can be seen more clearly.

Though simple, we use this telescope design for even the most sophisticated telescopes but there is one flaw. It uses light reflection to see things far away, so if anything gets in the way of the light, we can’t see it. We tried huge telescopes on the ground to some avail but not everything we hoped to see. We finally decided not to filter out our atmosphere but to get out of our atmosphere and put a telescope in space. That’s why in 1990 we put the Hubble Space Telescope in orbit 250 miles from Earth.

What does the Hubble Space Telescope do?

Almost everyone has heard the name Hubble, and some know it is a telescope, but the general population does not understand what it actually does. The typical answer is that it looks at stars but we can use the telescopes on the ground to see the stars. The real answer is the Hubble Space Telescope looks at light! It is true that stars give off light, but so do planets, comets, and moons, but that is only part of space. What about the part of space that doesn’t give off light? On Earth light has a source that can be controlled so it is easy to focus on the object you want to see. In space, we can only see what light is shining on, so to better understand what the Hubble Space Telescope does, you must first understand how light works in space.

Tune in next time when we explain how light works in space, how the Hubble Space Telescope uses that light to make the discoveries we have, and how those discoveries helped us to move into the next generation of telescopes!

2017-05-01T10:02:39+00:00 April 30th, 2017|